a) Field of the Invention
The present invention is directed to an articulated fitting for seats with an adjustable backrest, in particular motor vehicle seats, in which a stationary articulated part associated with the seat part and a swivelable articulated part associated with the backrest are connected with one another via a swivel axle. An adjusting and fixing device is provided which determines the position of both articulated parts relative to one another and is constructed as a gear unit. The swivel axle has an eccentric portion for supporting one articulated part. This eccentric portion is formed by two wedge segments which embrace a portion of a driver of the swivel axle and are inclined relative to one another, by a driver arm engaging between the narrow sides of the wedge segments, and by an energy accumulator which presses apart the wide sides of the wedge segments. The swivel axle of each articulated fitting has a central receptacle serving to connect with a transmission rod so as to be fixed with respect to rotation relative thereto, which transmission rod couples the two articulated fittings of a seat with one another.
b) Description of the Related Art
DE 30 13 304 C2 describes an articulated fitting of the type mentioned above in which the driver for the wedge segments is constructed as a disk and is connected with the swivel axle portion so as to be fixed with respect to rotation relative thereto, e.g., by means of a press fit, shrink fit or the like. The disk-shaped driver can have integrally formed driver projections. Such a construction of a disk-shaped driver is not easy to manufacture due to the radial jump in the region of the driver projections. However, forming the driver projections as pins, stop cams or the like secured to the driver disk requires separate structural component parts which are rigidly connected with the driver disk. In order to transmit torque from the articulated fitting arranged on one longitudinal side of the seat to the articulated fitting arranged on the opposite longitudinal side of the seat, a transmission rod is provided which engages in a non-circular recess of the swivel axle and accordingly couples the swivel axles of the two articulated fittings. However, this requires that the centers of the swivel axle portions having the recesses for the transmission rods be exactly aligned in order to prevent the occurrence of constraining forces during adjustment. This necessitates a tedious and costly assembly process.
Moreover, DE 39 41 215 A1 discloses another articulated fitting of the type mentioned above in which a centering segment is arranged adjacent to the wedge segments to improve the running properties of the articulated fitting and reduce wear during the adjustment phase. Further, an embodiment example of this articulated fitting of the prior art set forth in DE 39 41 215 A1 shows a driver which is arranged laterally adjacent to the swivel axle formed by a bearing bush and engages by its driver arm between the wedge segments supported on the bearing bush on the one hand and the centering segment on the other hand. The driver and bearing bush presented in this solution are also separate structural component parts which must be coupled with a transmission rod and supported thereon. In this solution, it is also necessary for the swivel axles of the articulated fittings arranged on both longitudinal sides of the seat to be exactly aligned with one another to prevent constraining forces during the adjustment phase.